# Sendblue vs WhatsApp Business Platform (Cloud API)

> WhatsApp Business Platform (Cloud API) scores 67.1 (B) on agent readiness against Sendblue's 61.7 (C), and leads in 4 of 7 scored categories. Sendblue leads on agent ergonomics and maintenance & community. Both do messaging inbound. Category scores, facts, verdicts and agent…

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- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

WhatsApp Business Platform (Cloud API) scores 67.1 (B) on agent readiness against Sendblue's 61.7 (C), and leads in 4 of 7 scored categories. Sendblue leads on agent ergonomics and maintenance & community. Both do messaging inbound.

- Sendblue: grade C, 61.7/100, rank #358 of 722. Markdown https://www.anchorterminal.com/tools/sendblue.md · JSON https://www.anchorterminal.com/api/v1/tools/sendblue.json
- WhatsApp Business Platform (Cloud API): grade B, 67.1/100, rank #218 of 722. Markdown https://www.anchorterminal.com/tools/whatsapp-cloud-api.md · JSON https://www.anchorterminal.com/api/v1/tools/whatsapp-cloud-api.json

## Which one, for what

### Sendblue (C)

Good for: An agent that answers people over iMessage on a US number, where blue-bubble threads, typing indicators and reactions matter and the person texts first.

Ahead on:
- Agent ergonomics, 76 against 67
- Maintenance & community, 72 against 34

Also in its favour:
- Runs on your own machine
- Free to start without a card

Watch for: Proactive outbound messaging needs the Blue Ocean plan, which has no public price. The $100 AI Agent plan is inbound-first

### WhatsApp Business Platform (Cloud API) (B)

Good for: The direct route to WhatsApp for a business messaging its own customers, with no reseller fee.

Ahead on:
- Reliability, 80 against 71
- Schema & documentation, 82 against 66
- Security & auth, 67 against 46
- Transparency & trust, 82 against 58

Watch for: A person has to create a Meta account, a developer app, a business portfolio and a system user in a browser before any token exists


## Score by category

| Category | Weight | Sendblue | WhatsApp Business Platform (Cloud API) | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 71 | 80 | WhatsApp Business Platform (Cloud API) +9 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 66 | 82 | WhatsApp Business Platform (Cloud API) +16 |
| Agent ergonomics | 13% (16.2 this run) | 76 | 67 | Sendblue +9 |
| Security & auth | 14% (17.5 this run) | 46 | 67 | WhatsApp Business Platform (Cloud API) +21 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 72 | 34 | Sendblue +38 |
| Transparency & trust | 7% (8.8 this run) | 58 | 82 | WhatsApp Business Platform (Cloud API) +24 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **61.7 · C** | **67.1 · B** | |

## Facts side by side

| Fact | Sendblue | WhatsApp Business Platform (Cloud API) |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Round One, Inc. | Meta Platforms, Inc. |
| Hosted endpoint | `https://api.sendblue.com` | `https://graph.facebook.com` |
| Transports | HTTP, stdio | HTTP |
| Auth | API key | OAuth |
| Pricing | Freemium | Pay per use |
| x402 | no | no |
| Licence | Proprietary service under Round One, Inc.'s terms of service. The TypeScript and Python SDKs and the MCP server are Apache-2.0, and the CLI is MIT | Proprietary service under the Meta Terms for WhatsApp Business Platform. The OpenAPI document in facebook/openapi is MIT |
| Tools exposed | 18 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-07 | 2026-08-11 |
| Terms last updated | 2025-03-19 | couldn't be read |
| Privacy policy last updated | 2024-05-01 | 2025-08-22 |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | not found in the text | couldn't be read |
| Terms restrict benchmarking | not found in the text | couldn't be read |
| Terms or service can change without notice | not found in the text | couldn't be read |
| Arbitration or class-action waiver | yes | couldn't be read |
| Popularity | 250k npm/wk, 40k PyPI/wk | none |

## Verdicts

**Sendblue.** Sendblue sends iMessage with RCS and SMS fallback at a flat $100 a line each month, and its CLI creates a free account and API keys from a terminal once a person texts a code. Proactive outbound messaging is sold through sales, no OpenAPI file is published, and the MCP package the docs install dates from August 2025.

**WhatsApp Business Platform (Cloud API).** The first-party WhatsApp API has a public OpenAPI document, Markdown docs with llms.txt, numeric rate limits and a test number that sends without a payment method. Setup needs a person in three Meta dashboards, no idempotency key was found for sends, and Meta's terms restrict general-purpose AI assistants on the platform.

## Before you call either

### Sendblue

1. Send `from_number` on every request. Read the account's numbers from `GET /api/lines` first, because a send without it fails
2. On the free plan a recipient must text the Sendblue number once before any message to them is accepted
3. Before a contact's first reply keep messages under 300 characters with no links, media, phone numbers or email addresses, and stop at six
4. Branch on `error_key` in an HTTP 400 decline and don't retry it. Only HTTP 429 clears by waiting
5. Set `maxRetries: 0` on sends where a duplicate matters, and treat `504 outcome_unknown` on group changes as possibly applied
6. Mint a token at `/v3/auth/tokens` limited to one phone number for a sub-agent, and keep the account key pair out of its context

### WhatsApp Business Platform (Cloud API)

1. Check when the user last wrote. Free-form messages are accepted only within 24 hours of the user's last message. After that, send an approved template.
2. Record the message id from each send and match it to `messages` webhook statuses. Many failures arrive only by webhook, and no idempotency key was found.
3. On error 130429 or 131056 wait and retry. Meta's guidance for the per-recipient limit is 4^X seconds, with X rising by one per failure.
4. Verify `X-Hub-Signature-256` with the app secret on every webhook, and deduplicate, because failed deliveries are retried for up to 7 days.
5. Request `health_status` on the phone number before a campaign to see whether the app, business, account, number and template can send.

## Questions

### Which is better for AI agents, Sendblue or WhatsApp Business Platform (Cloud API)?

WhatsApp Business Platform (Cloud API) scores 67.1 (B) on agent readiness against Sendblue's 61.7 (C), and leads in 4 of 7 scored categories. Sendblue leads on agent ergonomics and maintenance & community.

### Do Sendblue and WhatsApp Business Platform (Cloud API) need an API key?

Sendblue needs an API key. WhatsApp Business Platform (Cloud API) uses an OAuth sign-in.

### Can an agent call Sendblue and WhatsApp Business Platform (Cloud API) without installing anything?

Yes. Sendblue has a hosted endpoint at https://api.sendblue.com and WhatsApp Business Platform (Cloud API) at https://graph.facebook.com.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/sendblue-vs-whatsapp-cloud-api.json, and with the fewest tokens: https://www.anchorterminal.com/compare/sendblue-vs-whatsapp-cloud-api.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "sendblue", "b": "whatsapp-cloud-api"}`. From a terminal: `anchor compare sendblue whatsapp-cloud-api`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/sendblue.json and https://www.anchorterminal.com/api/v1/tools/whatsapp-cloud-api.json

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